Package 'csvy'

Dictionary of column classes for reading data

Description

Dictionary of column classes for reading data

Usage

colclass_dict

Format

An object of class character of length 7.

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Import and Export CSV Data With a YAML Metadata Header

Description

CSVY is a file format that combines the simplicity of CSV (comma-separated values) with the metadata of other plain text and binary formats (JSON, XML, Stata, etc.). The CSVY file specification is simple: place a YAML header on top of a regular CSV. The csvy package implements this format using two functions: write_csvy and read_csvy.

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Retrieve YAML header from file

Description

Note that this assumes only one Yaml header, starting on the first line of the file.

Usage

get_yaml_header(file, yaml_rxp = "^\\#*---[[:space:]]*$", verbose = TRUE)

Arguments

file	A character string or R connection specifying a file.
yaml_rxp	Regular expression for parsing YAML header
verbose	Logical. If TRUE, print warning if no header found.

Value

Character vector of lines containing YAML header, or 'NULL' if no YAML header found.

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Import CSVY data

Description

Import CSVY data as a data.frame

Usage

read_csvy(file, metadata = NULL, stringsAsFactors = FALSE,
  detect_metadata = TRUE, ...)

Arguments

file	A character string or R connection specifying a file.
metadata	Optionally, a character string specifying a YAML (“.yaml”) or JSON (“.json”) file containing metadata (in lieu of including it in the header of the file).
stringsAsFactors	A logical specifying whether to treat character columns as factors. Passed to read.csv or fread depending on the value of method. Ignored for method = 'readr' which never returns factors.
detect_metadata	A logical specifying whether to auto-detect a metadata file if none is specified (and if no header is found).
...	Additional arguments passed to fread.

See Also

write_csvy

Examples

read_csvy(system.file("examples", "example1.csvy", package = "csvy"))

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Read metadata

Description

Read csvy metadata from an external .yml/.yaml or .json file

Usage

read_metadata(file)

Arguments

file	full path of file from which to read the metadata.

Value

the metadata as a list

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Export CSVY data

Description

Export data.frame to CSVY

Usage

write_csvy(x, file, metadata = NULL, sep = ",", dec = ".",
  comment_header = if (is.null(metadata)) TRUE else FALSE,
  name = deparse(substitute(x)), metadata_only = FALSE, ...)

Arguments

x	A data.frame.
file	A character string or R connection specifying a file.
metadata	Optionally, a character string specifying a YAML (“.yaml”) or JSON (“.json”) file to write the metadata (in lieu of including it in the header of the file).
sep	A character string specifying a between-field separator. Passed to fwrite.
dec	A character string specifying a within-field separator. Passed to fwrite.
comment_header	A logical indicating whether to comment the lines containing the YAML front matter. Default is TRUE.
name	A character string specifying a name for the dataset.
metadata_only	A logical indicating whether only the metadata should be produced (no CSV component).
...	Additional arguments passed to fwrite.

See Also

write_csvy

Examples

library("datasets")
write_csvy(head(iris))

# write yaml w/o comment charaters
write_csvy(head(iris), comment_header = FALSE)

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Write csvy metadata

Description

Write csvy metadata to an external .yml/.yaml or .json file

Usage

write_metadata(metadata_list = NULL, file = NULL)

Arguments

metadata_list	metadata to be stored. Must be valid as per yaml::as.yaml() or jsonlite::write_json() for that particular output type.
file	full path of file in which to save the metadata.

Value

NULL (invisibly)

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